Biomedical Dept of Internal Medicine and Medical Specialties, University of Palermo, Palermo, Italy. Division of Endocrinology, Diabetes and Metabolism, University of South Carolina School of Medicine, Columbia, SC, USA. Biomedical Dept of Internal Medicine and Medical Specialties, University of Palermo, Palermo, Italy. draggana.nikolic@gmail.com. Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy. Laboratory of Cardiovascular Endocrinology, IRCCS San Raffaele Pisana, Rome, Italy. Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Roma Open University, Rome, Italy. Institute of Biomedicine and Molecular Immunology "Alberto Monroy", National Research Council (CNR), Palermo, Italy. Department of Internal Medicine, Regional Center for Diabetology, Partinico Hospital, Partinico, Italy. IRCCS MultiMedica, Milan, Italy. Diabetes and Endocrinology, Insititut d'Investigacions Biomèdiques August Pi i Sunyer and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Hospital Clínic Barcelona, Barcelona, Spain.